990FX Motherboard Roundup with Thuban and Bulldozer – A Second Wind for ASUS, Gigabyte, MSI and Biostar

ASUS Sabertooth 990FX BIOS

The ASUS BIOS is now firmly cemented in a motherboard reviewer's mind.  That tactic of ‘easy organizational screen’ followed by ‘advanced mode’ has been integrated and copied by other manufacturers wanting to build on the success of the ASUS system.  With the Sabertooth series, the focus of the product in terms of hardware and software is stability and the ability to manipulate everything to do with cooling.  For the BIOS however, ASUS has decided to stick with what works best, and we get a similar system to their channel products to play around with.

Easy mode comes with the information we want from a BIOS – the name of the motherboard, the processor (and speed of that processor), the memory (and the speed of the memory), temperatures, voltages and fan speeds.   Users can use the ‘system performance’ presets in the EZ BIOS for low power consumption or a fast overclock, as well as manipulate the boot priority by dragging and dropping.  To boot from a device, press F8 and a menu appears to select the appropriate device.

To manipulate the system in terms of CPU clocks, the advanced mode is the place to be.  ASUS’ AI Tweaker has been a feature in their graphical BIOS implementations since the early Sandy Bridge concepts, and here it is utilized on their 990FX boards.  Full control of the CPU frequency and multipliers are available, as well as Digi+ VRM settings and memory.  The only confusing part for me was the selection of the OC Tuner, ASUS’ automatic overclocking option.  In previous iterations I have used, a menu comes up with Yes/No selection.  In this instance, if a user selects it, it causes an automatic reboot and implements the OC Tuner. 

SATA controls are also a little different – rather than being directly underneath the South Bridge controls, they are in their own little subsection of the SATA controls.  By default, ASUS bucks the trend by implementing AHCI as standard (compared to other vendors on 990FX who have IDE as standard).

Fan controls for the BIOS are disappointingly limited; the chassis controls are all grouped under one selection.  This is due to the strength of the operating system software, which provides a much more detailed selection of options for the user.  I would like to see in the future the functionality of the OS software implemented into the BIOS at some stage, however if that was the case then we may come up against the 8 MB size limitations of the BIOS system.

Flashing the BIOS requires using the EZ Flash sub-software (in the BIOS).  Just put the file on a USB stick and put it in a non-USB 3.0 slot (I suggest non-USB 3.0, just for compatibility) and select it in EZ Flash.

Overclocking

Overclocking performance on the Sabertooth 990FX experienced distinct extremes.  On the one hand the Thuban X6-1100T processor gave respectable overclocks for our voltage limitations, however attempting to overclock the Bulldozer FX-8150 came up against a pretty solid brick wall quite a lot of the time.

Options for overclocking come in the form of OC Tuner, ASUS’ auto overclocking software, or a manual overclock.  The best way to perform the manual overclock was to attempt speeds in the OS with the TurboV software (part of ASUS’ AI Suite), and then attempt them permanently in the BIOS.  As always with these AMD processors, users should be careful regarding NB Link (Northbridge) and HT Link (HyperTransport) speeds which could increase with base frequency (FSB) increases.

Overclock recovery on the Sabertooth 990FX was not as sleek as other ASUS products – while a bad overclock was caught the majority of the time, infrequently the system would refuse to catch it.  A hard reset was required to catch the overclock, at which the settings could be retrieved.

Each overclock is tested for stability and temperature by a full run of PovRay and Blender, two 3D image generators that utilize both the CPU and memory.  Our methodology is as follows:

1) Auto Overclock
2a) Manual Overclock, High FSB (Tune to a high FSB, then raise multiplier)
2b) Manual Overclock, Stock FSB, High Multiplier
2c) Manual Overclock, Combination

Thuban X6-1100T Overclock

1) Auto Overclock: With the OC Tuner located in the BIOS, the system increased the base frequency from 200.7 MHz to 232.77 MHz, leaving the multiplier at 16.5x, giving a total increase in speed from 3.3 GHz to 3.84 GHz, more than a 16% overclock.  This in turn boosted the memory a similar amount (default 1333 MHz to 1550 MHz).

For the Manual Overclock settings, the CPU voltage was set to 1.5 volts, the memory to 1.65 volts, and the NB/HT Links kept as near to 2000 MHz as possible.  As this is an ASUS board, we also placed all the Digi+ VRM settings to their extreme to maximize the available overclock.

2a) Manual Overclock, High FSB: The Sabertooth does well in the high FSB test, however at 340 MHz and 330 MHz, while the system reached the operating system, gave a blue screen under high load (suggesting more voltage needed).  However at our voltage limit, an overclock of 325 MHz was stable with a multiplier of 12.5x, giving a total speed of 4062 MHz.  This gave 1.512 volts at full load, reaching 58°C under PovRay and 57°C with Blender.

2b) Manual Overclock, High Multiplier: Luckily, multiplier testing is straightforward.  We were able to reach 20.5x multiplier at 200 MHz, giving a total CPU speed of 4100 MHz.  However at this setting, the CPU voltage rose to 1.560 volts under load, but this only gave 57°C under both PovRay and Blender.

2c) Combination Overclock: In order to keep the memory straps nice and usable, the aim is to get the best overclock under 233 MHz or 280 MHz.  At 280 MHz, the system was not being nice, even at 4060 MHz.  With 233 MHz, the system was limited to the 17x multiplier, giving 3961 MHz, worse than both the high FSB test and the high multiplier test.  At this setting, the system gave 1.560 volts to the CPU under load, and reached 57°C with PovRay (56°C with Blender).

Bulldozer FX-8150 Overclock

1) Auto Overclock: Using the OC Tuner setting in the BIOS, the motherboard gave the processor a bump in the base frequency from 200.7 MHz to 230.78 MHz, resulting in a 15 % overclock (4154 MHz total), just above the basic Turbo boost for single core operation.  The memory received a similar boost, jumping from 1333 MHz on Auto to 1532 MHz.

For the Manual Overclock settings, the CPU voltage was set to 1.5 volts, the memory to 1.65 volts, and the NB/HT Links kept as near to 2000 MHz as possible.  As this is an ASUS board, we also placed all the Digi+ VRM settings to their extreme to maximize the available overclock.

2a) Manual Overclocking, High FSB: Starting at 340 MHz, the level at which the X6 1100T processor was able to boot into the operating system, unfortunately this was a no-go.  Dialing back the base frequency to 330 MHz gave a successful load into the operating system, however at multipliers which I know this processor works (14.5x for 4785 MHz and 14.0x for 4620 MHz), the system would rise above 90°C during the PovRay/Blender stress tests.  At this temperature (either CPU or VRM), even with ASUS’ raised Digi+ VRM options, the system would declock to 3600 MHz, its base multiplier.

2b) Manual Overclocking, High Multiplier: With the high multiplier settings, the CPU temperature limit was also hit early on, showcasing 90°C+ at the 22x multiplier.  This means that to get anywhere with this CPU on this board, more substantial cooling is needed than the AMD All-In-One Liquid cooler which was used as the standard cooler in these tests.  As a result, 2c) was not performed.